Slack adjuster



E. LATSHAW SLACK ADJUSTER March 3, 1931.

Filed April 18. 1928 mw llbl irri;

"iras ear ELMER LATSEAW, OAF PHILADELPHIA, PENNSYLVANIA, ASSIGN'ORy'.IVO J. G'. BRELL CQVIPANY, Oli"k IPHELADELPHKA, PENNSYLVANIA, A`CORPORATION Fv ENNSYI- venin SLACK ADJUSTER Application filed April 18,

automatic slack adjuster that shall constitute an improvement over thatdisclosed in the patent to Leonhauser, No. 1,631,961, dated June 111,1927, in thatI it is simpler in construction, easier to repair, lessexpensive to manufacture and more eliicient in operation'.

Another object of my invention is to provide a slack adjuster, whereinthe lengthv 'of jThe-lower ends 9 and 10 of the live lever 1 and theconnecting member may be readily shortened, as well as increased, byhand without the necessity for disconnectingVv the connecting memberfrom its associated linkage, las is necessary inv theaforesaidrLeonhauser patent.

videan improved form ofv supporting means for the adjusting sleeve,wherein the clutch parts enclosed thereby may be more eftlciently sealedagainstV undesirable material.

` A still further object of my invention is to provide an automaticslack adjuster, wherein the cushion spring, which serves to maintain theratchet members in resilient engagement, may be prevented trombeingdistorted when the adjusting sleeve is operated.

vA still further object of my invention is to l provide a slack adjustercomprising a movable member, a head for said member, an ady relation tothe head and affording the sleeve a bearing surface, and a springextending between said means and the 'bearing member,

' tending to prevent'an axial movement of the sleeve in the direction ofthe head.-

With these and other objects and' applica-V. tions lin mind, myinvention further consists i Vin the details ofconstruction andoperation and arrangement, hereinafter described and '45 claimed andillustrated in the accompanying j drawing, wherein Fig. 1 is asideelevational viewl of an auto-L matic slack adjuster embodying myinvention; and j Fig. 2 is a plan view, partly in section, of

vpinsV 1A- and 15.

A further object of myinventicn is to pro-V j Vvided with a threadedboring 16 for the recep- 1928. semi No. 270,935.

the structure of Fig. 1, omitting thevlive and y dead levers.

Referring to the drawing, the slack adj usterl therein shown comprises apair of live and dead levers 1 and 2 which `are respectively connectedto the usual brake beams 3 and 4: by means of clevises 5 and 6. rlhelive lever 1 may be actuated by means of an'operating link Z whichextends from an upper endV 8 thereof to the usual control apparatus (notshown).

the dead lever 2, respectively vare operatively ing member 11 arerespectivelyconnected to the live lever 1 and to the dead lever 2 bypivot rlhe head member 13 is, protioii of a correspondingly threadedend: portion 17 of a rotary rod18; f `VAn opposite end portion 19 o'l"the rod 18 is extended into a boring 21 formed in an adjacent endportion 22 of the head member 12, thereby` affording miV the rod 18'arotatable -niounting at one end l thereof. Y

. The rod 18 may be rotatablyloclred to the head niember12 againstrelative longitudinal movement by means of Va nut 23 which is mounted ona threaded end A24 of a .projecting portion 25 ot therotary rod 18. Theprojecting portion 25 extends through an `aperture 26 in a wall 27 otthehead member 12 and throughspring plate 23a. Movement of the rod 18relative to the head 12 in one direction isprevented Vby the nut 23engaging one side of the wall 27, while an opposite movement isprevente'dby theend of the rod lSengaging the vopposite side of the wall27. rflic rod, however, may bereadily detached `from the head 12 merelyby removing the nut 28.l

' My invention furtherv contemplates the provision of means, whereby thespacing of the heads 12 and 13, and consequently the brake beams 5 and6, "may be automatically controlledwhen the movement of the live anddeadA levers 1 and2 exceeds a predetermined value. To ythis end, Iprovide a bell-crank v member 28 which ispivotally mounted on the pin14, one arm 29 being in operative relation toone side of a pin olwhichismounted onthe live lever 1. An opposite side of the pin 81 is inoperative relation to an arm 82 adjustably mounted on an outer endportion 88 of the arm 29. rl`he spacing of the arms 29 and 82 is suchthat the fulcrumed member 28 is actuated only when the movement of thelive lever 1 exceeds that necessary for normal operation of the bra-kebeams 5 and 8.

rAnother arm of-the bell-rank-lever 28 is provided with a ball endportion 85 which lits between spaced side walls 88 and 87 extendingoutwardly from the adjacent end portion of a cylindrical adjustingsleeve 88. rlhe adjusting sleeve 88 is provided with a ring member 89which is rigidly secured to an inner surface 42 thereof. The innerdiameter of the ring member 89 is slightly greater than the outerdiameter of the rod end portion 18 so as to be in spaced relationthereto, thereby decreasing the number of bearingl surfaces andconsequently the problem' of lubrication. @ne end face of the ringmember 89 Vis provided with ratchet teeth 48 which co-act with ratchetteeth 44 formed on an acent end face of a member rigidly secured to therotary rod 18. lllhile ratchet teeth 48, 44 have been specified, anyother form of clutch device may be employed, wherein a turning of thesleeve member 88 in one direction causes a corresponding movement of therotary member 18, but an opposite movement of the adjusting sleeve 88fails to cause the actuation of the rotary member 18.

Tlie ratchet member 45 is provided with a bearng surface 48 for theadjacent end portion of the adjusting sleeve 88, so tliat the sleeve 88may be suitably supported adjacent to the ratchet teeth 48, 44. rl`hepassage of foreign material between the adjusting sleeve 88 and the baring surface 46 into the ratchet teeth 44 is prevented by means of agrease seal 47 which may be formed in the bearing surface 48. This sealmay comprise a plurality of spaced circular grooves 48 which are packedwith grease. The ratchet member is provided with a portion 49 which er.-tends beyond the outer end of the adjusting sleeve 88 and is hexagonalin form, permitting the same to be readily gripped by wrench or othertool and the 'rod 18 then turned by hand, in the event that it `isdesired to adjust manually the space between the heads 12 and`18 andconsequently the brake beams 5 and 8.

The end of the adjusting sleeve, 88, which is associated with the ballend 85 of the lever arml 84, may be supported by means of Va bearingring 51 Ywhich is loosely mounted on the rod 18 within the adjustingsleeve 88 and positioned with one side thereof in abutting relation witha bearing surface 52 constituting an end wall of the supporting head 12.er grease seal is formed in the bearing surface 52 by means of acircular groove 58 which is filled with grease, thereby preventing thepassage of foreign material between the bearing member 51 and thesupportingl head 12 to the adjacent portion of the rotary member 18.

riChe ring member 51 is also provided with a bearing surface on theperiphery thereof which affords the adjacent end portion of the sleeve88 desired support. Foreign material may be prevented from workingbetween the adjusting sleeve 88 and the ring- 51 by means of a greaseseal which is formed in the bearing surface 54, this seal comprising aplurality of spaced circular grooves 55 which are filled with grease.rlhe grease seals in the spaced bearing surfaces 48 and 54 for theadjusting sleeve 88 thus prevent undesirable foreign material fromreaching the ratchet teeth 48, 44, as well as other roportions of theapparatus contained within the housing sleeve 88.

A resilient engagement may be maintained between the teeth 48, 44 of theratchet mem- 2 and 48 by means of a spring 57, which es the rod 18, oneend of the spring t against the rigid ratchet member 42 and the otherabutting against the bearing ring 51. Since the ring 51 is looselymounted on the rod 18, distortion of Vthe spring 57 is sleeve 88 isturned. `The ring 51, in addition to providing the supporting surface 54for the adjusting sleeve 88 and closing one end thereof against theadmission of foreign material, may also serve to divide up the dif- Hference lin rotation between the adjusting member 88 and the rod 18,themovement of the bearing ring'51 being approximately one-half thedifference between the two. Moreover, should the ring become fastenedAto the rotary member 18 or the sleeve 88, there is vstill one bearingsurface provided.

ln operation, when the operating link 7 is moved, say, to the right, thebrake beams 8 and 4 are moved sufficiently to cause theapplication ofthe brakes (not shown). Should there be an undesirable amount-oflooseness or slack inthe mechanism, the pin 81 engages tbe arm 82 beforethe brakes are finally applied causing the turning of the bell-cranklever 28. The movement ofthe bell-crank lever 28 causes the turning ofthe adjusting sleeve 88 but the ratchet teeth 48 Vof the member 42merelyslide over the teeth 44 of the ratchet member 45, being pressed againstthe same by thespring 57.

lillhen the brakes are -released by an opposite movement of the link?,the pin 81 engages thearm 29 of thebell-crank ylever 28, causing theadjusting slee-ve '88to be turned in the opposite direction. The ratchetteeth 48 of the member-42 now. engage the ratchet teeth 44 of the member45 and cause the rotation of the rod 18. As a result, the space betweenthe heads 12 and 18, and consequentprevented when the adjusting ly thebrake beams 5 and V6, is automatically decreased to a desired value,depending upon the spacing between the arms 29 and 32 oi the bell-crankmember 28. It is noted that the variation in the slack occurs when. thebrakes are released, thereby decreasing the power necessary to eiiectthe adjustment.

Should it be desirable to shorten the space between the heads 12 and 13by hand, it is Y necessary only to move the sleeve 38 axially of the rod18 in the direction or' the head 12 a relatively small ldistance inorder to disengage the ratchet members 42 and 45, whereupon the rod 18may be readily turned by a wrench secured to the hexagonal portion 49rof the ratchet member 44. l/Vhen the desired adjustmenthas beeneffected, the member 38 may be released from its retracted position, thespring 57 forcing the same forwardly, so that the ratchet teeth 43 ofthe member 42 are again in engagement with the teeth 44 of the member45. Such means of adjustmentV may be easily and quickly eii'ectedwithout the necessity for disconnecting the head 13 from its associatedlinkage which has heretofore been the practice. While l have shown onlyone form of embodiment of my invention. for the purpose of describingthe same and illustrating its principles of construction and operation,it is apparent that various changes and modiiica-y tions may be madetherein without departing from the spirit of my invention. I desire,therefore, that only such limitations shall be imposed thereon asareindicated inthe appended claims or asrare demanded by the prior art.

I claim:

1. In a slack adjuster, the combination with a movable member, of amovable housing sleeve, disengageable clutch means for ly shiftableouter wall, co-acting ratchet clutch elements carried by said outer walland the rotatable element, and a light spring extending between one endof the chamber and the first-named clutch element.

4. In a slack adjuster, a rotatable member,

spaced opposedelements carried thereby, one 1 `oi" said membershaving'the inner end thereoperatively associating said sleeve and saidmember, and resilient means operative on said clutch means so positionedas to be housed by said sleeve,said clutchmeans be- 1 ing renderedineffective upon a movement thereof vagainst the force of said resilientmeans. permitting the independent operation of said movable member. Y v

2. 1n slack adjusting mechanism, a rotata-r ble member, a sleevesurrounding said rotata-v ble member, spaced Vmembers supporting thesleeve from the rotatable member, a ratchet clutch having an elementsecured to the ro- Y

